One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,6)(3,7,8,5)(9,10)(11,14)(12,15)(13,16)(17,19)(18,22)(20,23)(21,24)(25,26)(27,32)(28,34)(29,35)(30,44)(31,36)(33,40)(37,46)(38,47)(39,49)(41,50)(42,48)(43,51)(45,53)(52,55)(54,56)(1,3)(2,5)(4,8)(6,7)(9,10)(11,17)(12,15)(13,16)(14,19)(18,23)(20,22)(21,24)(25,27,31,39)(26,32,36,49)(28,37,41,54)(29,42,30,38)(33,45,51,55)(34,46,50,56)(35,48,44,47)(40,53,43,52)(9,11,13,19)(10,14,16,17)(12,20,21,18)(15,23,24,22)(25,28)(26,33)(27,37)(29,40)(30,43)(31,41)(32,45)(34,44)(35,50)(36,51)(38,52)(39,54)(42,53)(46,47)(48,56)(49,55)(3,8)(5,7)(9,12,13,21)(10,15,16,24)(11,18,19,20)(14,22,17,23)(25,28)(26,34)(27,37)(29,43)(30,40)(31,41)(32,46)(33,44)(35,51)(36,50)(38,53)(39,54)(42,52)(45,47)(48,55)(49,56)(10,16)(14,17)(15,24)(22,23)(25,29,31,30)(26,35,36,44)(27,38,39,42)(28,40,41,43)(32,47,49,48)(33,50,51,34)(37,52,54,53)(45,46,55,56)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.